This invention relates to automatic level control circuits and more particularly to such circuits to maintain a constant level for a local oscillator signal applied to a frequency mixer.
Automatic level control circuits are often used to keep a local oscillator signal level constant when coupled to frequency mixers. A constant local oscillator signal level is important to maintain a smooth conversion loss over the RF (radio frequency) frequency band. Generally the automatic level control signal is obtained by sampling and detecting a portion of the local oscillator signal power before it enters the mixer.